[deliverable/linux.git] / include / linux / nfs_page.h

/*
 * linux/include/linux/nfs_page.h
 *
 * Copyright (C) 2000 Trond Myklebust
 *
 * NFS page cache wrapper.
 */

#ifndef _LINUX_NFS_PAGE_H
#define _LINUX_NFS_PAGE_H


#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/wait.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>

#include <linux/kref.h>

/*
 * Valid flags for the radix tree
 */
#define NFS_PAGE_TAG_LOCKED	0
#define NFS_PAGE_TAG_COMMIT	1

/*
 * Valid flags for a dirty buffer
 */
enum {
	PG_BUSY = 0,
	PG_MAPPED,
	PG_CLEAN,
	PG_NEED_COMMIT,
	PG_NEED_RESCHED,
	PG_PNFS_COMMIT,
};

struct nfs_inode;
struct nfs_page {
	union {
		struct list_head	wb_list;	/* Defines state of page: */
		struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */
	};
	struct page		*wb_page;	/* page to read in/write out */
	struct nfs_open_context	*wb_context;	/* File state context info */
	struct nfs_lock_context	*wb_lock_context;	/* lock context info */
	atomic_t		wb_complete;	/* i/os we're waiting for */
	pgoff_t			wb_index;	/* Offset >> PAGE_CACHE_SHIFT */
	unsigned int		wb_offset,	/* Offset & ~PAGE_CACHE_MASK */
				wb_pgbase,	/* Start of page data */
				wb_bytes;	/* Length of request */
	struct kref		wb_kref;	/* reference count */
	unsigned long		wb_flags;
	struct nfs_writeverf	wb_verf;	/* Commit cookie */
};

struct nfs_pageio_descriptor {
	struct list_head	pg_list;
	unsigned long		pg_bytes_written;
	size_t			pg_count;
	size_t			pg_bsize;
	unsigned int		pg_base;
	char			pg_moreio;

	struct inode		*pg_inode;
	int			(*pg_doio)(struct nfs_pageio_descriptor *);
	int 			pg_ioflags;
	int			pg_error;
	struct pnfs_layout_segment *pg_lseg;
	bool			(*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
};

#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))

extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
					    struct inode *inode,
					    struct page *page,
					    unsigned int offset,
					    unsigned int count);
extern	void nfs_release_request(struct nfs_page *req);


extern	int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
			  pgoff_t idx_start, unsigned int npages, int tag);
extern	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
			     struct inode *inode,
			     int (*doio)(struct nfs_pageio_descriptor *desc),
			     size_t bsize,
			     int how);
extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
				   struct nfs_page *);
extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern  int nfs_wait_on_request(struct nfs_page *);
extern	void nfs_unlock_request(struct nfs_page *req);
extern	int nfs_set_page_tag_locked(struct nfs_page *req);
extern  void nfs_clear_page_tag_locked(struct nfs_page *req);


/*
 * Lock the page of an asynchronous request without getting a new reference
 */
static inline int
nfs_lock_request_dontget(struct nfs_page *req)
{
	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}

/**
 * nfs_list_add_request - Insert a request into a list
 * @req: request
 * @head: head of list into which to insert the request.
 */
static inline void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
	list_add_tail(&req->wb_list, head);
}


/**
 * nfs_list_remove_request - Remove a request from its wb_list
 * @req: request
 */
static inline void
nfs_list_remove_request(struct nfs_page *req)
{
	if (list_empty(&req->wb_list))
		return;
	list_del_init(&req->wb_list);
}

static inline struct nfs_page *
nfs_list_entry(struct list_head *head)
{
	return list_entry(head, struct nfs_page, wb_list);
}

static inline
loff_t req_offset(struct nfs_page *req)
{
	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
}

#endif /* _LINUX_NFS_PAGE_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/linux/nfs_page.h
	3	*
	4	* Copyright (C) 2000 Trond Myklebust
	5	*
	6	* NFS page cache wrapper.
	7	*/
	8
	9	#ifndef _LINUX_NFS_PAGE_H
	10	#define _LINUX_NFS_PAGE_H
	11
	12
	13	#include <linux/list.h>
	14	#include <linux/pagemap.h>
	15	#include <linux/wait.h>
1da177e4 LT	16	#include <linux/sunrpc/auth.h>
	17	#include <linux/nfs_xdr.h>
	18
c03b4024	19	#include <linux/kref.h>
1da177e4	20
c6a556b8 TM	21	/*
	22	* Valid flags for the radix tree
	23	*/
9fd367f0	24	#define NFS_PAGE_TAG_LOCKED 0
5c369683	25	#define NFS_PAGE_TAG_COMMIT 1
c6a556b8	26
1da177e4 LT	27	/*
	28	* Valid flags for a dirty buffer
	29	*/
e468bae9 TM	30	enum {
e468bae9 TM	31	PG_BUSY = 0,
2df485a7	32	PG_MAPPED,
e468bae9 TM	33	PG_CLEAN,
	34	PG_NEED_COMMIT,
	35	PG_NEED_RESCHED,
a861a1e1	36	PG_PNFS_COMMIT,
e468bae9	37	};
1da177e4	38
3da28eb1	39	struct nfs_inode;
1da177e4	40	struct nfs_page {
a861a1e1 FI	41	union {
	42	struct list_head wb_list; /* Defines state of page: */
	43	struct pnfs_layout_segment wb_commit_lseg; / Used when PG_PNFS_COMMIT set */
	44	};
1da177e4 LT	45	struct page wb_page; / page to read in/write out */
1da177e4 LT	46	struct nfs_open_context wb_context; / File state context info */
f11ac8db	47	struct nfs_lock_context wb_lock_context; / lock context info */
1da177e4	48	atomic_t wb_complete; /* i/os we're waiting for */
ca52fec1	49	pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
1da177e4 LT	50	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	51	wb_pgbase, /* Start of page data */
	52	wb_bytes; /* Length of request */
c03b4024	53	struct kref wb_kref; /* reference count */
1da177e4 LT	54	unsigned long wb_flags;
	55	struct nfs_writeverf wb_verf; /* Commit cookie */
	56	};
	57
d8a5ad75 TM	58	struct nfs_pageio_descriptor {
d8a5ad75 TM	59	struct list_head pg_list;
bcb71bba	60	unsigned long pg_bytes_written;
d8a5ad75 TM	61	size_t pg_count;
	62	size_t pg_bsize;
	63	unsigned int pg_base;
b31268ac	64	char pg_moreio;
bcb71bba TM	65
bcb71bba TM	66	struct inode *pg_inode;
c76069bd	67	int (pg_doio)(struct nfs_pageio_descriptor );
bcb71bba TM	68	int pg_ioflags;
bcb71bba TM	69	int pg_error;
94ad1c80	70	struct pnfs_layout_segment *pg_lseg;
18ad0a9f	71	bool (pg_test)(struct nfs_pageio_descriptor , struct nfs_page , struct nfs_page );
d8a5ad75 TM	72	};
d8a5ad75 TM	73
1da177e4	74	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	75
	76	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	77	struct inode *inode,
	78	struct page *page,
	79	unsigned int offset,
	80	unsigned int count);
1da177e4 LT	81	extern void nfs_release_request(struct nfs_page *req);
	82
	83
5c369683 TM	84	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head dst,
5c369683 TM	85	pgoff_t idx_start, unsigned int npages, int tag);
bcb71bba TM	86	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	87	struct inode *inode,
c76069bd	88	int (doio)(struct nfs_pageio_descriptor desc),
bcb71bba TM	89	size_t bsize,
bcb71bba TM	90	int how);
8b09bee3 TM	91	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	92	struct nfs_page *);
bcb71bba	93	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	94	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
1da177e4 LT	95	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	96	extern void nfs_unlock_request(struct nfs_page *req);
acee478a	97	extern int nfs_set_page_tag_locked(struct nfs_page *req);
9fd367f0	98	extern void nfs_clear_page_tag_locked(struct nfs_page *req);
c6a556b8	99
1da177e4 LT	100
1da177e4 LT	101	/*
c03b4024	102	* Lock the page of an asynchronous request without getting a new reference
1da177e4 LT	103	*/
	104	static inline int
	105	nfs_lock_request_dontget(struct nfs_page *req)
	106	{
a911fd9a	107	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	108	}
1da177e4 LT	109
3da28eb1 TM	110	/**
	111	* nfs_list_add_request - Insert a request into a list
	112	* @req: request
	113	* @head: head of list into which to insert the request.
	114	*/
	115	static inline void
	116	nfs_list_add_request(struct nfs_page req, struct list_head head)
	117	{
	118	list_add_tail(&req->wb_list, head);
3da28eb1 TM	119	}
3da28eb1 TM	120
1da177e4 LT	121
	122	/**
	123	* nfs_list_remove_request - Remove a request from its wb_list
	124	* @req: request
	125	*/
	126	static inline void
	127	nfs_list_remove_request(struct nfs_page *req)
	128	{
	129	if (list_empty(&req->wb_list))
	130	return;
1da177e4	131	list_del_init(&req->wb_list);
1da177e4 LT	132	}
1da177e4 LT	133
1da177e4 LT	134	static inline struct nfs_page *
	135	nfs_list_entry(struct list_head *head)
	136	{
	137	return list_entry(head, struct nfs_page, wb_list);
	138	}
	139
	140	static inline
	141	loff_t req_offset(struct nfs_page *req)
	142	{
	143	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	144	}
	145
	146	#endif /* _LINUX_NFS_PAGE_H */